General Notes: Apart from improving yield/recovery of desired component(s), MBDS also adds value in many other ways, such as:
Benefits
- Plus any value for Secondary Recoverable Solvent
- Plus gain of additional capacity due to reduction in Batch Time
- Plus any energy savings in condenser and re-boiler due to reduction in Reflux Ratio (see Case Study, ROI-II)
- Plus environmental gain due to lower carbon footprint
- Plus ability to create recipe for streams hitherto un-processed (see Case Study, ROI-II)
- Plus higher price realization due to higher purity of recovered solvent
- Plant had never distilled this system
- A lot of solvent had accumulated in the storage tank
- MIBK purity ~99.5 wt% & Moisture ~0.8 wt%
- MIBK recovery ≥ 80.0 %
- Condenser min. temp. approach ≥ 5 °C
- Reflux rate < 5 m3/hr
- Re-boiler min. temp. approach ≥ 5 °C
| 1 | Typical Batch Distillation Size | 5000 | liter/Batch | ||
| 2 | Since these streams are being sold, as spent, the current recovery is set to: (In fact in this case, this stream has never been processed in the plant) | 0% | |||
| 3 | Benefit analysis is done based on Main Recoverable Solvent value | ||||
| 4 | The spent solvent is sold at Rs.10/- per liter | ||||
| 5 | Price of fresh MIBK is 110/- per liter | ||||
| 6 | Feed Composition is given below: | ||||
| Component | wt% |
| Cyclohexane | 22.69 |
| Toluene | 2.29 |
| MIBK | 73.01 |
| Water | 2.00 |
| System/Column | C2 | |
| Available, | Lit Per Month | 20000 |
| Column Thruput Rate, | Lit/Batch | 5000 |
| Number of Batch/Month | 4 | |
| Main Recoverable Solvent | MIBK | |
| Secondary Recoverable Solvent | CH, Toluene | |
| Main Recoverable Solvent, | wt% | 73.0% |
| Recoverable Solvent, | Lit/Month | 14600 |
| Current Recovery | 0% | |
| Current Loss, | Lit/Month | 14600 |
| Additional Recovery, % of Loss | 90% | 90% |
| Additional Recovery, Lit/Month | 13140 | |
| Spent Realization, | Rs/Lit | 10 |
| Fresh Solvent Price, | Rs/Lit | 110 |
| Net Gain, | Rs/Lit | 100 |
| Money Saved, | Lakh/Month | 13.1 |
- The plant actually achieved a recovery of 95%+
- But even taking 90% recovery, the monthly benefit is 13 lakhs
- That gives a payback of less than a month
